A group of 49 randomly selected construction workers has a mean age of 22.4 years with a standard deviation of 3.8. According to a recent survey, the mean age should be mu=21.9. Test this hypothesis by constructing a 98% confidence interval for the population mean.

Answer 1

21. 9 -2.33* 3.8 /sqrt((49)), 21. 9 + 2.33* 3.8 /sqrt((49))
(20.64, 23.16)

98% confidence interval contain